opendaylight/md-sal/sal-dom-xsql/src/main/java/org/opendaylight/controller/md/sal/dom/xsql/XSQLThreadPool.java

   1 /*
   2  * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.md.sal.dom.xsql;
  10
  11 import java.util.LinkedList;
  12
  13 public class XSQLThreadPool {
  14     private LinkedList<Runnable> tasks = new LinkedList<>();
  15     private int threadCount = 0;
  16     private int maxThreadCount = 10;
  17     private String threadPoolName = "Simple Thread Pool";
  18     private int waitTimeForIdle = 10000;
  19     private int maxQueueSize = -1;
  20     public Object waitForSlotSync = new Object();
  21
  22     public XSQLThreadPool(int _maxThreadCount, String name,
  23         int _waitTimeForIdle) {
  24         this.maxThreadCount = _maxThreadCount;
  25         this.threadPoolName = name;
  26         this.waitTimeForIdle = _waitTimeForIdle;
  27     }
  28
  29     public void addTask(Runnable r) {
  30         synchronized (tasks) {
  31             tasks.add(r);
  32             tasks.notifyAll();
  33             if (threadCount < maxThreadCount) {
  34                 threadCount++;
  35                 new WorkerThread(threadCount).start();
  36             }
  37         }
  38     }
  39
  40     private class WorkerThread extends Thread {
  41
  42         private long lastTimeExecuted = System.currentTimeMillis();
  43
  44         public WorkerThread(int threadNumber) {
  45             super(
  46                 "Thread #" + threadNumber + " Of Threadpool " + threadPoolName);
  47         }
  48
  49         public void run() {
  50             Runnable runthis = null;
  51             while (true) {
  52                 runthis = null;
  53                 if (maxQueueSize != -1) {
  54                     synchronized (waitForSlotSync) {
  55                         if (tasks.size() < maxQueueSize) {
  56                             waitForSlotSync.notifyAll();
  57                         }
  58                     }
  59                 }
  60                 synchronized (tasks) {
  61                     if (tasks.isEmpty()) {
  62                         try {
  63                             tasks.wait(2000);
  64                         } catch (Exception err) {
  65                         }
  66                     }
  67
  68                     if (!tasks.isEmpty()) {
  69                         runthis = tasks.removeFirst();
  70                     }
  71                 }
  72                 if (runthis != null) {
  73                     try {
  74                         runthis.run();
  75                     } catch (Exception err) {
  76                         err.printStackTrace();
  77                     }
  78                     lastTimeExecuted = System.currentTimeMillis();
  79                 }
  80                 if (System.currentTimeMillis() - lastTimeExecuted
  81                     > waitTimeForIdle) {
  82                     break;
  83                 }
  84             }
  85             synchronized (tasks) {
  86                 threadCount--;
  87             }
  88         }
  89     }
  90
  91     public int getNumberOfThreads() {
  92         return threadCount;
  93     }
  94
  95     public void waitForSlot() {
  96         if (tasks.size() > maxQueueSize) {
  97             synchronized (waitForSlotSync) {
  98                 try {
  99                     waitForSlotSync.wait();
 100                 } catch (Exception err) {
 101                     err.printStackTrace();
 102                 }
 103             }
 104         }
 105     }
 106
 107     public boolean isEmpty() {
 108         if (this.threadCount == 0) {
 109             return true;
 110         }
 111         return false;
 112     }
 113
 114     public void setMaxQueueSize(int size) {
 115         this.maxQueueSize = size;
 116     }
 117
 118 }